Cutting and mulching equipment is often used to cut away and/or clear brush including tall grass, plants, weeds, shrubs, wood chips, branches and the like. A common method for clearing brush involves a rotary brush cutter. Such a cutter has a blade that rotates in a plane generally parallel to the ground such that it generally uniformly cuts the brush.
A brush cutter may be mounted on a tractor loader(Bobcat) or other such surface loading machinery or equipment. The brush cutter is mounted generally on the front of a machine or cab such that the brush cutter clears a path for the operator and equipment on which the brush cutter is mounted.
A brush cutter may pose a risk of injury to an operator. A common problem occurs where an object is thrown from the cutting area of the brush cutter. The object may be a twig, a rock, or any other object that may pose a risk to an operator. There is a potential that such an object could hit an operator and cause injury. This problem is more pronounced when the rear portion of the brush cutter is raised off the ground with respect to the front portion, the rear portion being the portion nearest the operator.
It is thus preferable that the brush cutter have a protective mechanism, such as an automatic shut-down mechanism, for when the brush cutter is raised to a dangerous height off of the ground.
One mechanism in the prior art involves a set of rollers positioned at a rear portion of a brush cutter. These rollers are heavy so that they maintain contact with the ground. If the brush cutter is raised to a predetermined height, the rollers will drop down with respect to the brush cutter housing and cause the automatic shut-off mechanism to be actuated. A problem with this apparatus is that the rollers may cause an unnecessary shut-off if the brush cutter travels over a hole or crevice area that causes the rollers to drop down to the predetermined shut-off distance.
A similar problem can occur when the brush cutter travels over a log. The rollers will drop down once they have rolled over the log, thus unnecessarily implementing operation of the shut-off mechanism.
Another problem with this mechanism is that it adds significant weight to the brush cutter, thus limiting the vast majority of cabs that can carry the weight of the shut-off mechanism.
Another mechanism in the prior art involves the use of an apparatus wherein a shut-off mechanism is initiated based on the difference between the height of the brush cutter with respect to the height of a cab. This apparatus includes a chain having a first end bolted to the brush cutter and a second end secured to a chassis of the cab, to thus limit the height to which the brush cutter can be lifted off of the ground with respect to the cab. A problem with this mechanism is that the brush cutter may be located over an inclined surface with respect to the cab, thus unnecessarily initiating the shut-off mechanism.
Another problem with these prior art mechanisms is that they lack shut-off devices that extend along the entire length of the side of the brush cutter to prevent debris from escaping through the sides of the brush cutter. Also, these mechanisms can become caught on the ground and other debris during operation, requiring the operator to shut down the machine and clean them off. Another problem with these mechanisms is that they are independent of the electrical mechanism, or motor, that runs the brush cutter. Thus, the safety mechanisms may be removed from the brush cutter without affecting operation. For example, the chain or rollers may be removed from the brush cutter and the brush cutter will still be able to operate, thus making the effectiveness of the safety mechanism moot.
The present invention provides for an improved brush cutter that addresses these shortcomings.